Galactocerebroside and glucocerebroside will be the primary topics. The soluble proteins of rat brain will be purified further and characterized to determine the factors that influence their ability to solubilize the cerebrosides. Additional attempts will be made to isolate the glucosidase that hydrolyzes glucocerebroside. Additional structural analogs of the lipids will be synthesized and tested in vitro, in mice, and in brain cell preparations to determine the effects of interfering with cerebroside metabolism. It is possible that we will be able to develop model forms of Gaucher's disease and to ameliorate the disorder by slowing the rate of glucocerebroside formation. BIBLIOGRAPHIC REFERENCES: The effects of N-hexyl-O-glucosyl sphingosine on normal cultured human fibroblasts: a chemical model for Gaucher's disease. K.R. Warren, I.A. Schafer, J.C. Sullivan, M. Petrelli, and N.S. Radin. J. Lipid Res. 17: 132-138 (1976). Glucosyltransferases of rat brain that make cerebrosides: substrate specificity, inhibitors, and abnormal products. K.R. Warren, R.S. Misra, R.C. Arora, and N.S. Radin. J. Neurochem. 26: 1063-1072 (1076).